HaloMods "Classic" Read-only Archive

if your not going to help then dont post and what i was trying to say was i have the pc one, not xbox

I have read all of the tutorials I can find but I still cant figure it out. when I open HMT 3 it opens, no problem but when i tell it to open a map it asks me if I want to decompress it. If i say yes it says that its not avalible but if I press no it doesnt do anything. am i missing a step, i have ....